There are at least a handful of cards that I think realistically have a shot at helping Humans keep up with the rest of the insanely new powerful cards that will likely reshape Modern as we know it
Geralf decks are multifarious, synergizing with high-toughness creatures, zombies, and flying synergies alike
Risky Research Spider-Byte, Web Warden Spider-Gwen, Free Spirit Spider-Man, Web Slinger Wild Pack Suad Daily Bugle Reporter Masked Meower Shock Eerie Gravestoen Flying Octobot Grow Extra Arms Kraven's Cats Lurking Lizards Merciless Enforcers Romantic Rendezvous Scorpion's Sting Scout the City Selfless Police Captain Unstable Experiment Doc Ock's Henchmen Guy in the Chair Mechanical Mobster Tomstone, Career Criminal Web Up Oscorp Research Team Scorpion, Seething Striker Spider-Islanders Doc Ock, Sinister Scientist Double Trouble Spider-Man, Brooklyn Visionary Starling, Aerial Alley Stegron the Dinosaur Man Venom, Evil Unleashed Venom's Hunger Shocker, Unshakable Spider-Rex, Daring Dino Aunt May Beetle, Legacy Criminal SP Piloted by Peni Origin of Spider-Man Island Plains Mountain Forest Swamp Is the Spider-Man MTG set legal
The obvious cards for pairing with Sunken Citadel are Field of Ruin + Demolition Field or Nykthos, but there are almost certainly other possibilities out there
As long as it isnt removed, they don't have a way to shuffle back in
